Method of treating a fabric web with a liquid

ABSTRACT

A method of and apparatus for treating a fabric web with a liquid, in which the fabric web is passed through a bath of the liquid and around and in contact with the perforated periphery of a rotating drum at least partially immersed in the liquid. The drum contains two axially-spaced impellers which circulate the liquid to flow substantially radially through the fabric web and perforated drum periphery and substantially axially within the drum interior and through the ends of the drum. The liquid flow is preferably inwards through the fabric web and drum perforations, and outwards through the ends of the drum. The axial positioning of, or spacing between, the impellers is adjustable, thereby to confine the flow through the fabric web and drum perforations to an adjustably selected region in the length of the drum which substantially coincides with the width of the fabric web.

United States Patent 91 1 1 3,8l9,325

Bates June 25, 1974 METHOD OF TREATING A FABRIC WEB Primary Examiner-Harvey C. Hornsby WITH A LIQUID Assistant Examiner-Philip R. Coe

[76] Inventor: Emile Bernard Bates, l l Barrington Attorney Agent or Firm-Paul & Paul -Rd., Leicester, England Filed: June 14, 1973 ABSTRACT [21] Appl. No.: 369,992 A method of and apparatus for treating a fabric web with a liquid, in which the fabric web is passed Related Appl'catmn Data through a bath of the liquid and around and in contact Continuation of Set June 23, 1971, with the perforated periphery of a rotating drum at abandonedleast partially immersed in the liquid. The drum contains two axially-spaced impellers which circulate the Cl 8/151 26/DIG- 1, 68/DIG- 5 liquid to flow substantially radially through the fabric [51] Int. Cl. B051: 3/132 web d rf rated drum periphery and substantially [58] Field of Search 8/l49.'l, 149.3, 151; axially within the drum interior and through the ends 68/DIG- 184; 26/DIG- l of the drum. The liquid flow is preferably inwards through the fabric web and drum perforations, and

[ References Cited outwards through the ends of the drum. The axial po- UNITED STATES PATENTS sitioning of, or spacing between, the impellers is ad- 2,613,522 10/1952 Heffelflngcr 26/DIG. 1 justflble, thereby to confine the flow through the 3,467,975 9/1969 Fleissner ..68/DIG. 5 ric e nd ru pe ora ons o an adj ta y s 3,476,367 1 1/I969 Fleissner 68/DlG. 5 lected region in the length of the drum which substan- 3,5l 1,066 5/1970 Fleissner 68/184 X tially coincides with the width of the fabric web 3.606,?74 9/l97l Fleissncr 68/DIG. 5 v

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METHOD OF TREATING A FABRIC WEB WITH A LIQUID This is a continuation of US. Pat. application Ser.

No. 155,859 Filed June 23, 1971 now abandoned.

CROSS-REFERENCE TO RELATED APPLICATIONS Reference is made to British Pat. applications Nos. 6706/68 dated Feb. '10, 1968 and Pat. No.- 16819/71 of May 25, 1971, both in the name of Inventions Development Limited.

This invention concerns a method of treating a fabric web with liquid. It is particularly concerned with the scouring and/or dyeing of a fabric web (e.g. a knitted web) in a continuous manner.

The broad principles sofar employed in the continuous treatment of a fabric web with a liquid, such for example as a scouring liquid or dye liquor, can be classified in one or more of the following catagories:

a. A steady progression of the fabric'web through a hot liquid.

b. An oscillation of the fabric web, in a direction normal to its'plane, as it is drawn over immersed rollers;

c. The passage of the fabric web through a plurality of squeeze rollers which are either submerged in, or are above, the liquid;

d. The spraying of the liquid against the surface of the fabric web. v

In none of these is there any appreciable force tending to urge large volumes of the liquid through the fabric web and although in a treatment of catagory (d) there is admittedly a tendency to force the liquid through the fabric yet with a closely woven fabric the spray impact is so transient that the passage of large volume is impossible, and with delicate open-weave fabrics or knitted fabrics a fierce spray can damage the fabric.

The present invention provides a method for the con tinuous treatment of a fabric web with a liquid, which comprises passing the fabric through a band of the liquid and around, and in contact with, the perforated periphery of a rotating drum immersed in the liquid, and calculating the liquid to flow substantially radially through the fabric web and the perforated drum periphery and substantially axially within the drum interior and through the end of the drum. The liquid flow through the fabric web and drum perforations can be inwards or outwards. It is preferably confined substantially to the length of the drum covered by the fabric web. Specifically it can be confined to an adjustably selected region in the axial length of the drum which region is so selected that it coincides with the width of the fabric web.

According'to any important feature of the invention the requisite impelling force is applied, within the drum, to the liquid. The force is preferably applied, in opposite axial directions, from two regions spaced apart axially within the drum, thereby creating, within the drum, a zone in which the pressure differs from that obtaining outside the drum periphery.

It will be appreciated that since the web travels around the periphery of the rotating drum each point in the length of the web remains in contact with that periphery for an appreciable time and is therefore subjected for an appreciable time to the liquid flow. Thus,

although with a dense fabric the rate of flow through any given area of the fabric web may be relatively low, yet the total volumeof liquid flowing through that area will be substantial. In the case of a delicate fabric the flow is preferably inwards so that the fabric web is supported by the drum.

A fabric web (e.g. a knitted web) exhibits a tendency to curl at its edges and it has been ascertained that if in the carrying out the foregoing method the fabric web is supplied to the perforated drum periphery with the curl presented at the outer face of the web, the liquid flow can be employed to extend or smooth the fabric web widthwise and also to remove the edge curl.

The invention also provides apparatus for the continuous treatment of a fabric web with a liquid, comprising a container for the lquid, a drum having a perforated periphery rotatably mounted in the container, guides for conducting the fabric web into and out of the container, the web passing around, and in contact with the perforated drum periphery within the container, and means inside the drum to impel the liquid to circulate, substantially radially through the web and the drum perforations and substantially axially of the drum interior and through the ends of drum, between the drum interior'and the liquid-containing space of the container exterior to the drum. There may be means for confining the liquid flow through the fabric web and perforations substantially to the length of the drum contacted by the fabric web.

Specifically, the impelling means may comprise two spaced impellers inside the drum acting to urge the liquid in two opposite axial directions. There may be means whereby the spacing of the two impellers may be that Patent.

In order that the present invention may be better understood reference will now be made to the accompanying drawings which are to some extent diagrammatic and in which:

FIG. 1 is a sectional elevation of one portion of apparatus according to the invention;

FIG. 2 is a sectional elevation of a following portion of the apparatus, while FIG. 3 is a plan view of part of the apparatus as shown in FIGS. 1 and 2,

FIGS. 4 and 5 are diagrammatic illustrations, in sectional elevation and plan respectively, of a further form of the apparatus.

It is intended that the apparatus illustrated in the accompanying drawings shall be associated with an edgeguiding mechanism or stentering machine according to British Pat. No. 1,014,765. In FIG. 1 the fabric web to be treated, held on the flexible bands 11a, 11b of that Patent (the conjoint web and bands having the reference F.B.), travels to the left through guides 14 into a container 15 containing a bath of a treating liquid for example a dyeing liquor. In that container the flexible bands, with the fabric web held thereon, pass partly round the peripheries of perforated drums 16 to 19 and emerge through the nip between guiding and squeezing rollers 20, 21.

Perforated drum 16 is a guide drum. In each of the perforated drums l7, 18, 19 there is a pair of axially spaced impellers 22a, 22b arranged to operate in opposite axial directions so as to draw the liquid into each drum through the ends thereof and to force it out, substantially radially, through the perforations of the drum and through the fabric web or alternatively in the reverse direction. Each impeller may consist of a plurality of radiating blades, the pitch angle of the blades of one impeller being opposite to that of the blades of the other impeller so that if both of the impellers are rotated in the same direction they tend to urge the liquid in opposite directions axially of the drum. A suitable drive mechanism is provided for rotating each drum and its impellers and the latter may be rotated at the same speed as or at a higher speed than the drum; the impellers may be rotated in the same direction or in the opposite direction to the drum.

It is to be understood however, that according to the direction in which the impellers are rotated having regard to the pitch of their blades the flow may be inwards from each end of the drum into the space between the impellers and thence out through the perforations of the drum, or in the opposite direction, i.e., inwards through the perforations into that space and then outwards towards each end of the drum. Liquid flow necessarily takes place around each end of the drum either from the drum interior to the ambient space surrounding it or in the reverse direction. Suitable guiding surfaces may be provided in the container at the ends of the drum so as to ensure a smooth liquid flow. The surfaces may be partly toroidal (as illustrated at 33a, 33b in FIG. 3). It may here be mentioned that FIG. 3 illustrates the two directions of liquid flowin relation to the drums 17 and 18.

The location of each impeller may be adjustable axially of the drum. For this purpose each impeller may comprise a central boss which is slidable along a shaft but which may be clamped to the shaft at any suitable location axially of the latter. Thus the spacing between the impellers may be adjusted to co-incide substantially with the width of the fabric web so that the liquid flow through the drum perforations is confined substantially to the length of the drum contacted by the fabric web.

It is also within the scope of the invention to adjust the position of the impellers in conformity with adjustment between the spacing of the flexible bands, the adjustment mechanism for the impellers being coupled to the adjustment mechanism for the band spacing. Although drum [6 is shown in FIG. 1 as a guide drum, it may be provided with impellers.

From the rollers 20,21 the bands with the attached fabric web pass through an entry slot 30 into a further container 23 (FIG. 2) where they are passed partly round the peripheries of guide roller 24, perforated drum 25 and roller 26. From the latter they pass to roller 27, perforated drum 28, and roller 29, leaving the container by way of an exit slot 31. On emerging from the latter the fabric web F is stripped from the flexible bands 11a, 11b and the latter are returned to the stentering machine as indicated by arrows B in FIGS. 1 and 2.

It will be understood that the spacing between rollers 24 and 26 and between 27 and 29 determines the distance around the periphery of the respective drums 25, 28 which the fabric web contacts, and for this purpose the spacing between the said rollers of either or each pair may be adjustable.

The container 23 may be a drying chamber or may contain a bath of a further treatment liquid, for example a liquid for rinsing or scouring.

The perforated drum 25 is provided in its interior with a pair of spaced impellers 32a, 32b functioning in substantially the same manner as the previously mentioned impellers 22a, 22b. In this instance however, they draw the air or liquid through the fabric and drum perforations into the drum interior and expel it at the ends of the drum. The partly toroidal guides previously mentioned are indicated at 33a, 33b, FIG. 3. These impellers may be driven and adjusted substantially in the manner described in British Pat. application No. 36678/67 Pat. Ser. No. 1,170,688 co-pending with the corresponding British. Alternatively, the bosses 34a, 34b of the respective impellers 32a, 32b may be adjustably clamped to the driving shaft 35.

The perforated drum 28 is mounted on a driving shaft 36. It may be equipped with impellers (not shown) similar to those of the drum 25.

If the container 23 is a drying chamber it is provided with suitable means, not shown, for heating the air which is circulated by the impellers 32a, 321), through the fabric web and drum. I

Referring to FIGS. 4 and 5, the fabric F is fed to the drum periphery through squeeze rollers 40a, 40b and is withdrawn from the drum periphery by draw-off rollers 41a, 41b. The rollers 40a, 40b supply the fabric at a linear speed which is greater eg 20 percent than the peripheral speed of the drum l7 and the rollers 41a, 41b draw the fabric away from the drum at a linear speed which is less than the peripheral speed (e.g. about percent).

The liquid in the tank 15 is maintained at such a level L that the upper part of the periphery of the drum is slightly protruded above it and that the fabric makes initial contact and final contact with the drum periphery at regions also slightly spaced above that level. For this purpose, the tank is provided with a constant level outlet 42. A liquid supply means is indicated at 43.

At the opposite ends of the drum, within the tank, there are concave guide devices 44,45 which serve to direct the liquid issuing from the ends of the drum along the exterior of the drum to a central zone. Each of these devices may be part-toroidal, having an axis coincident with the drum axis. Alternatively, each device may consist of two concave guides such as 44a, 44b, and 45a, 45b disposed in a vertical position at opposite sides of the drum axis. Additionally, convex guide means 46,47 are provided at opposite sides of the drum axis. These guide means may be part-toroidal and concentric with the drum axis, or may consist of vertical members 46a, 46b and 47a, 47b spaced apart at on posite ends of the drum.

The fabric web F makes initial contact with the drum periphery with a width Fw and with its edges curled as at Fc, the curl being presented at the outer face of the fabric. The liquid width engaging this outer face of the fabric at the region of initial contact of initial contact of the fabric with the drum and for some distance thereafter not only has a component of flow inwards through the fabric and the drum periphery but also has a component of flow outwards towards the ends of the drum over the outer face of the fabric. The effectof this latter component is progressively to eliminate the curl at the edges and to stretch or smooth the fabric to its full width WF.

In order to confine the fabric flow within the drum substantially to axial directions and to eliminate or reduce any outwards or centrifugal spin of the liquid from the tips of the impellers, the tips of each impeller 22a, 22b are provided with a cylindrical shroud indicated at 48a, 48b.

What is claimed is:

l. A method of continuous treatment of a fabric web with aliquid, wherein the fabric has a tendency to curl at its edges, comprising the steps of:

A. providing a drum rotating in the liquid,

1. with an upper portion of the peripheral surface of the drum protruding above the liquid level so that the drum is incompletely submerged in the liquid,

B. delivering the web to the rotating drum at a location on the peripheral surface thereof above the liquid level,

l. with the web delivery to the drum surface being at a greater linear speed than that of the periphery of the drum, and

2. with the web as delivered to the surface of the drum i. being of an initial width as measured axially along the peripheral surface of the drum and,

ii. with the axially spaced edges of the web being curled outwardly of the surface of the drum, C. passing the fabric web through a bath of the liquid as the drum rotates in the liquid, 1. with the web disposed on the peripheral surface of the drum, D. circulating the liquid to flow axially outwardly of opposite ends of the drum by, l. impelling it with spaced-apart impellers disposed inside the drum, I

2. while directing the liquid by means of guides disposed at ends of the drum and disposed partially over peripheral surface portionsof the drum to flow i. substantially radially inwardly through the fabric web and substantially only through portions of perforated drum periphery immersed in the liquid and covered by a web, including through edge portions of the web,

ii. with a componentof flow axially along the drum at locations that the flow engages the curled edges of the web, and with the flow component that engages the curled web edges,

a. uncurling the edges to cause the web edges to engage the drum and b. stretching the fabric axially of the drum to have a greater width as measured axially of the drum than its initial width as presented to the drum,

and v E. withdrawing the web from the drum after the web has passed through the liquid on the drum,

1. with the withdrawing taking place at a linear speed that is less than the linear speed of the periphery of the drum, and

2. at a location above the liquid level.

2. The method of claim 1 wherein the fabric web being treated is a knitted fabric.

3. The method of claim 1 wherein the step of directing the liquid includes the smooth guiding of the liquid flow through the use of a generally arcuate concave and convex guides, and wherein the impellingstep includes propelling of the liquid by means of propellers. 

2. with the web as delivered to the surface of the drum i. being of an initial width as measured axially along the peripheral surface of the drum and, ii. with the axially spaced edges of the web being curled outwardly of the surface of the drum, C. passing the fabric web through a bath of the liquid as the drum rotates in the liquid,
 2. while directing the liquid by means of guides disposed at ends of the drum and disposed partially over peripheral surface portions of the drum to flow i. substantially radially inwardly through the fabric web and substantially only through portions of perforated drum periphery immersed in the liquid and covered by a web, including through edge portions of the web, ii. with a component of flow axially along the drum at locations that the flow engages the curled edges of the web, and with the flow component that engages the curled web edges, a. uncurling the edges to cause the web edges to engage the drum and b. stretching the fabric axially of the drum to have a greater width as measured axially of the drum than its initial width as presented to the drum, and E. withdrawing the web from the drum after the web has passed through the liquid on the drum,
 2. at a location above the liquid level.
 2. The method of claim 1 wherein the fabric web being treated is a knitted fabric.
 3. The method of claim 1 wherein the step of directing the liquid includes the smooth guiding of the liquid flow through the use of a generally arcuate concave and convex guides, and wherein the impelling step includes propelling of the liquid by means of propellers. 